Auxiliary starting engine for locomotives



Dec. 16. 1924. 1,519,600 c. F. STREET AUXILIARY STARTING ENGINE FOR LOCOMOTIVES Filed Oct. 3, 1922 2 Sheets-Sheet J.

Dec. 1924- 1,519,600

C. F. STREET AUXILIARY STARTING ENGINE FOR LOCOMOTIVES Filed Oct. 5, 1922 2 Sheets-Sheet 2 Ewuamtoz Patented Dec. 16, 1924 UNlTED STATES CLEMENT F. STREET, OF GREENWICI-I, CONNECTICUT.

AUXILIARY STAR-TING ENGINE FOB LOCOMOTIVES.

Application filed October 3, 1922.

To all whom it may concern.

Be it known that I, CLEMENT F. STREET, a citizen of the United States, residing at Greenwich, in the county of Fairfield and State of Connecticut, have invented a certain new and useful Improvement in Auxiliary Starting Engines for Locomotives, of which improvement the following is a spec'- ticat'ion.

This invention relates to auxiliary starting engines for locomotives, such as are used to assist the main engine in starting heavy trains, and in propelling the same up grades, or wherever desired, when operating at low speeds.

My improved auxiliary engine is of the reciprocating type, having a piston operated by steam pressure in one direction, and by a spring during the return stroke, the piston rod being connected to operate a pawl and ratchet mechanism for turning one of the axles, such as shown and described in my prior application filed June 10, 1922, Serial No. 567,300.

()ne of the objects of my present invention is to provide an. improved forward locking and backward slipping mechanism comprising a pawl and ratchet, whereby the pawl may engage the ratchet teeth during the forward or working stroke of the engine and then be withdrawn during the return stroke so as to prevent dragging backward over the ratchet teeth. For this purpose I provide a fluid pressure device, preferably actuated by the steam employed for operating the engine, for engaging and disengaging the pawl.

In the accompanying drawings: Figure 1 is a vertical sectional view of an auxiliary engine and ratchet mechanism embodying my improvement; Fig. 2, a half transverse section and half end elevation; Fig. 3, a vertical section illustrating a modification of the pawl actuating mechanism; and, Fig. 1, an end elevation of the same.

According to the construction shown in Figs. 1 and 2, the auxiliary engine comprises a cylinder, 5, having piston, 6, with the rod, 7, pivotally connected at 21 to the oscillating arms, 22, mounted on an axle, 23, and carrying a pawl, 24, for engaging a ratchet wheel, 25, fixed upon the axle. The Supply of steam to the cylinder, 5, is controlled by a valve, 8, having a stem, 8, actuated by lever, 9% rod, 9, tappets, 10 and 11, and the actuating bar, 12, carried Serial No. 592,013.

by the piston rod, 7, the valve being shifted to one position by the tappet, 11, to admit steam into the cylinder, and then at the outer end of the stroke, shifted to the other position by tappet, 10, for closing the admission and opening the exhaust from the cylinder, whereupon the spring, 13, acts to move the piston through the return stroke. The pawl, 24-, is mounted on the pivot pin, 19, on the swinging arms, 22, said pin, 19, also being connected by means of a yoke and rod, 17, with the spring, 13, which acts to move the parts through the return stroke. The cylinder may be supported on trunnions, 83, and thrust bars, 30, may connect the same to rings, 31, rotatably mounted on the axle at both sides of the ratch: et wheel, 25.

As thus far described, the construction is substantially the same as that disclosed in my prior application above mentioned. In said prior construction, however, the pawl is held in engagement with the teeth of the ratchet wheel by the action of a spring during the entire period of operation of the auxiliary motor and consequently is dragged backward over the teeth of the wheel during the return stroke.

According to my present improvement, means are provided for raising said'pawl clear from the ratchet wheel during the re- V turn stroke, thereby avoiding the noise and wear of the parts at such times. For this purpose, there is shown a fluid pressure de vice comprising a small piston, 29, mounted in a chamber at the outer end of the piston rod, 7, and connected by means of a stem and yoke, 28, with the arm. 27, of the pawl, 24:. Steam or other fluid under pressure may be admitted from the cylinder, 5, to

the piston, 29, through a passage, 32, in

the piston rod, 7. A spring, 26, bears on the back of said piston, 29, and acts to raise the pawl, 24, out of engagement with the wheel, 25, when the fluid pressure is re leased.

lVhen it is desired to start the auxiliary motor, steam is supplied to the cylinder, 5. by opening the usual controlling valve, and then flows immediately through passage, 32, into the chamber of piston, 29, which moves outward against the spring, 26, and throws the pawl, 24, down into engagement with the teeth of ratchet wheel, 25. As the steam pressure then builds up in the cylinder, 5, the piston, 6, is moved outward and drives the axle, 23, through the rate'het mechanism" upon its forward stroke. At the end of the forward stroke, as the valve, 8, is reversed by the tappet mechanism, the exhaust is opened and the pressure isreleased from the chamber of piston, 29', and from the cylinder, 5. The spring, 26, then acts immediately to raise the pawl clear of the wheel, 25, while the main spring, 13, operates to return the parts to the first position, whereupon the steam is again admitted and the operation repeated. The steam pressure acts to positively hold the pawl against the ratchet wheel as long as there is pressure in the cylinder, 5, so that there is no danger oi the pawlslipping out of engagement with the ratchet teeth at this time.

As the spring, 26, is comparatively light, the steam pressure will besufticient to compress the same and throw the pawl into engagement before the main piston, 5, begins to move outward on its "forward stroke, thus utilizing the entire stroke of the piston in performing work, instead of using a portion of this movement for turning the pawl into and out of engagement with the wheel. Upon the'return stroke, the pawl is positively raised by the action of the spring, so as to prevent the same from dragging backward over the teeth, which action would produce obj'ectionablenoise and wear.

In the modification shown in Figs. 3 and t, the small piston, 29, is arranged vertically and bears upon a roller, 35, mounted on the -;paw.l, 24, ,while the springs, 26*,Lfor opposing the fluid pressure acting on the piston, 29?, .are located outsideand are-attached to the pawl and to the oscillating arms. The outer surfaceo'l the piston, 29?, is rounded to rock upon the roller, 35, during the oscillating movement of the arms, 22. The operation of this construction is, however, substantially similar to that above described, the springs, 26, acting .to raise the pawl clear of the ratchet wheel during the return stroke when the pressure is exhausted fromv the cylinder. v

My improvement also has the advantage that the pawl, is normally held clearof the ratchet wheel by a separate means wl iichis not dependent upon the movement of the main piston. Consequently the pawl will remain out of engagement when the auxiliary motor is cut out even it' the main return spring should break, or for any other, reason the piston should t'ailto return to its extreme inner position.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The combination with an engine cylinder and piston, of a. ratchet mechanism operated thereby, means for supplying pressure to said cylinder to operate said pawl and ratchet and means operable immediately upon the release of said pressure for throwmg the ratchet mechanism out 01": engagement during the return stroke of the piston.

2. The combination with an engine cylinder and piston, of a pawl and ratchet operated thereby,means operating automatically upon the admission of steam to said cylinder for throwing the pawl into engagement with ,der and piston, of a pawl and ratchet operated thereby, a fluid pressure actuated device for throwing said pawl into engage ment with the ratchet for the forward stroke of the piston, and a spring for raising the pawl clear of the ratchet during the return stroke.

4. The combination with an engine cylinder and piston, of a pawl and ratchet operated thereby, a fluid pressure actuated device for throwing the pawl into engagement with the ratchet, and means for supplying steam to said fluid pressure device and to said cylinder.

5. The combination with an engine cylinder and piston, of a pawl and ratchet operated thereby, a piston for throwing said pawl into engagement with the ratchet and a conduit for supplying steam from the cylinder to said pawl actuating piston.

6. The combination with an engine cylinder and piston, of a' pawl and ratchetopcrated thereby, a piston for throwing said pawl into engagement with the ratchet, a spring for raising the pawl clear of the ratchet upon the return stroke, and a conduit from the main cylinder to said pawl actuating piston.

7. The combination with an engine cylinder, piston andpiston rod, of a pawl and ratchet operated thereby, and a piston supported on said rod for throwing the pawl into engagement with the ratchet, said rod having a passage for supplying steam to said pawl actuating piston.

, 8. The combination with an engine cylinder, piston and piston rod, of oscillating arms pivotally connected to said rod, a pawl mounted on said arms, a ratchet wheel, a piston supported on said piston rod For throwing said pawl int-oengagement with the ratchet, and means for raising said pawl clear of the ratchet wheel upon the return stroke. of said piston.

9. The combination with an engine cylinder, piston and piston rod,,o't oscillating arms pivotally connected to said rod, a pawl. mounted on said arms, a ratchet wheel, piston supported on said piston rod and having a rounded end engaging said pawl, and aspiring acting on said pawl in opposition to the pressure on said piston.

10. The combination, with an engine cylinder and piston, of a pawl and ratchet operated thereby, means for throwing the pawl into engagement with the ratchet in advance of the beginning of the forward stroke of the piston, and means for raising said pawl clear of the ratchet for the return stroke of the piston.

11. The combination with an engine cylinder and piston of a pawl and ratchet operated thereby and a fluid pressure operated device for throwing the pawl into engagement with the ratchet on the forward stroke of the piston.

12. The combination with an engine cylinder and piston of a pawl and ratchet operated thereby and a fluid pressure operated device operable independently of the operation of said piston for throwing the said pawl into engagement with the ratchet in advance of the beginning of the forward stroke of the piston.

13. The combination, with an engine cylinder and piston, of a pawl and ratchet operated thereby, a spring for moving said piston through its return stroke, a device operated by the fluid under pressure from said cylinder for throwing said pawl into engagement with said ratchet, and a spring opposing said fluid pressure but adapted to be compressed by a. less degree of pressure than is required to compress the main return spring.

In testimony whereof I have hereunto set my hand.

CLEMENT F. STREET. 

